A drug-dealing solo mother known as "the queen of green" has been released from prison.

Chareese Gray was 26 when she was sentenced to three years and 10 months' prison in July 2012 for her part in a Napier cannabis operation that netted her and two partners up to $340,000 in four months.

Gray, the mother of three young children, was the main offender, and with two other solo mothers, Soraya Gray and Toni Stewart, ran a large-scale tinny operation from a state house.

A tinny is a tinfoil-wrapped package containing between 0.6 and 1.2 grams of cannabis that sells for about $20.

Business was booming during the four months, with the trio selling a tinny every minute and the number of customers so great that their cars would clog the street.

A police summary of facts said Gray organised a roster of "employees" to run the shop, with Stewart and others sending text messages to her as supplies ran down.

Police began a surveillance operation and at times observed cars parked up to four abreast in the cul-de-sac, with so many customers that on some days vehicles could not enter or leave.

In a decision released yesterday, the Parole Board said Gray had been released on January 15 but was recalled after a month because her "accommodation did not work out".

A new address was proposed at a hearing on April 3, when it was noted that her key supporter was of good character with no convictions.

"We are aware that the recalling board had some concern over the circumstances which led to the recall application but, overall, we believe Ms Gray is well-intentioned and is unlikely to return to the offending which brought her to prison," the board said.

Gray was granted release on April 16 with conditions including a curfew, not to consume or possess drugs or alcohol and to attend counselling sessions.